1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus capable of three-dimensional (3D) scanning.
2. Description of the Related Art
An ultrasonic diagnostic apparatus enables real-time acquisition of the pulsation of a heart or the motion of a fetus by simple operation of applying an ultrasonic probe to the surface of a body. Moreover, the ultrasonic diagnostic apparatus is free of exposure to radiation unlike X-rays and is thus highly secure and enables repeated examinations, which advantageously allows the use in, for example, obstetrical services or home care services. Further, the ultrasonic diagnostic apparatus is easy to use in that it is smaller in system scale than other diagnostic apparatuses such as X-ray, CT and MRI diagnostic apparatuses and can be easily moved to a bedside for examinations.
On the other hand, in a conventional examination using the ultrasonic diagnostic apparatus, an engineer who uses the ultrasonic probe for scanning changes the way of applying the probe to a region of interest to search for an image that makes the region of interest visible. The image thus obtained is preserved for a doctor to make a diagnosis.
In this case, in order to enable a field of view to be enlarged during the diagnosis by the doctor, a plurality of ultrasonic vibration units are provided to pick up two-dimensional images, and these two-dimensional images are synthesized and then displayed, as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 55-103839.
However, in such a method, the doctor interprets the image within the range of the two-dimensional images of a part which has been scanned by the engineer with suspicion. Therefore, the problem is that when the engineer has overlooked, for example, a tumor during the scanning with the ultrasonic probe, the doctor is unable to detect the tumor.
According to a method that tends to be used in the United States nowadays, the engineer only scans a predetermined region with the ultrasonic probe and preserves images of the region, and the doctor interprets the data and makes a diagnosis. That is to say, the engineer only performs scanning, and the doctor interprets the scanning result and makes a diagnosis. Thus, the engineer is in charge of scanning, and the doctor is in charge of interpretation, so that the two tasks are separated.
On the other hand, there has recently been developed and commercialized an apparatus which performs a so-called three-dimensional scan by applying an ultrasonic beam to a target part so that the target part can be volumetrically observed over time.
The advantage of such a three-dimensional scan capable of collecting volume data sets is that an objective diagnosis can be made. Specifically, as described above, it has heretofore been the case that the doctor makes a diagnosis only using the image of the part which has been scanned by the engineer with suspicion, so that the doctor is unable to detect any new problem in the parts overlooked by the engineer. However, the volume data sets acquired by the engineer by the three-dimensional scanning enables the doctor to reconstruct a given sectional image for observation, such that a diagnosis can be said to be more objective.
Accordingly, it is easily presumed that when the role of the engineer who performs scanning is clearly separated from the role of the doctor who makes a diagnosis as described above, the conventional interpretation with the two-dimensional images may be replaced the interpretation with the volume data sets.
On the other hand, in such a three-dimensional scan, the volume data sets are collected in real time. As a result, the volume of data handled is so great that considerable labor and time are required to reconstruct a given sectional image from the acquired volume data sets to detect a problematic part. Moreover, when the engineer is only allowed to simply perform a scan of the predetermined region as described above, images that can be acquired are limited by the way that the engineer applies the probe at the previous stage. Therefore, even if the doctor finds a part suspected of being affected by a disease as a result of interpreting the images, it is not possible to change the way of applying the probe to acquire an image that clearly shows the characteristics of this part. It is thus difficult to make a high-quality and accurate ultrasonic diagnosis.